The present invention relates to ophthalmic lenses. In particular, the invention provides lenses with surfaces designed using Chebyshev polynomials.
The use of ophthalmic lenses including, without limitation, contact lenses for the correction of ametropia is well known. A number of known methods exist for approximating the shape of the lens"" surface. For example, it is known to use splines, sine and cosine functions, exponential functions and logarithmic functions to define all or a part of a lens surface. However, the use of splines is disadvantageous in that some spline functions can become unconstrained at their outermost points resulting in oscillations between points. The other functions are problematic in that the ability to approximate a surface is limited by the equation used. Therefore, a need exists for a fitting method that overcomes some or all of these disadvantages.